@article{DAN_1979_244_6_a8,
     author = {V. B. Tvorogov},
     title = {The sharp front and singularities of solutions of a class of nonhyperbolic equations},
     journal = {Doklady Akademii Nauk},
     pages = {1327--1331},
     publisher = {mathdoc},
     volume = {244},
     number = {6},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1979_244_6_a8/}
}